# Definition:Ellipse/Vertex

## Definition

Consider an ellipse $K$.

A vertex of $K$ is either one of the endpoints of the major axis of $K$.

In the above diagram, $V_1$ and $V_2$ are the vertices of $K$.

## Also defined as

Some sources also classify the covertices as vertices.

That is, they define the vertices as the endpoints of both the major axis and the minor axis.

## Linguistic Note

The plural of vertex is vertices.

The word vertex is Latin for peak, from which the irregular plural form.